Actuating mechanism, particularyl for strip weldiers



May 28, 1957 M. M. SEELOFF EIAL ACTUATING MECHANISM, PARTICULARLY FORSTRIP WELDERS Original Filedlay 5, 4952 3 Sheets-Sheet l INVENTORSMED/IN u. SEELOFF ROBERT ANDERSON ATTO NEY ACTUATING MECHANISM,PARTICULARLY FOR STRIP WELDERS Original Filed May 5, 1952 May 28, 1957M. M. SEELOFF ETAL 3 Sheets-Sheet 2 INVENTORS MELVIN M. SEELDFF ROBERT WATTORNEY May 28, 1957 M. M. SEELOFF ETAL 2,794,111

ACTUATING MECHANISM, PARTICULARLY FOR STRIP WELDERS Original Filed Kay5, 1952 3 Sheets-Sheet 3 TNVENTORS 1 MELVIN u Siam- H aoscm' ANDERSON yd fzz ACTUATING MECHANISM, PARTICULARLY FOR STRIP WELDERS Melvin M.Seelofi and Robert Anderson, Warren, Ohio, assignors to TheTaylor-Winfield Corporation, Warren, Ghio, a corporation of OhioOriginal application May 5, 1952, Serial No. 286,041,

now Patent No. 2,758,184, dated August 7, 1956. Divided and thisapplication April 1, 1954, Serial No. 420,234

2 Claims. (Cl. 219-97) This application is a division of our co-pendingapplication Ser. No. 286,041, now U. S. Patent No. 2,758,184, filed May5, 1952, for Spacer Bar and Die Cleaner Mechanism for Strip Welders.

The present invention relates to actuating mechanisms, and moreparticularly to an improved actuating mechanism or system havingspecially advantageous use in the electric resistance flash welding artin the operation of large strip welders, for example.

It is an object of the present invention to provide a novel actuatingmechanism, particularly for use in driving the movable platen member ofa large strip welding machine whereby the operations of preparing themachine for welding and of aligning the strip material in the machineare substantially facilitated and simplified. Further in this regard, itis an object of the invention to provide a novel actuating mechanism forstrip welders whereby there may be readily incorporated into the weldingapparatus improved mechanisms for spacing the strip material for weldingand for cleaning the welding dies of random flash particles preparatoryto each welding operation.

In the practice of joining strip ends by resistance welding methods itis common to first align and clamp the adjacent strip ends inpredetermined spaced relationship in the welding machine, whereupon thewelding dies are closed together according to a predetermined pattern ofmovement whereby the strip ends are first flashed or softened and thenmoved forcibly together or upse to fuse the separate strip sections intoa continuous length of material.

To properly align and space the strip ends prior to welding it has beenproposed to employ a suitable gauge bar which is inserted between thewelding dies so that the strip ends may be moved into abutting relationwith the gauge bar and thereby be spaced and aligned with substantialprecision. Heretofore, for this purpose, it has been common to employ avertically movable gauge bar having tapering gauge faces thereon so thatthe gauge'bar could be removed from between the strip sections withoutdamaging the same. We have found this type of gauge device to beunsatisfactory in certain respects, however, particularly in that theskewed gauging faces tend to cause misalignment of the adjacent stripends, and this is particularly noticeable in the welding of lightmaterials.

On the other hand, the use of gauging devices having parallel gaugefaces has been heretofore deemed impractical since in order to removethe gauge bar from between the strip sections it is necessary to backoff the strip sections somewhat, a timeand power-consuming operation inlarge institutions due to the necessarily large size of the actuatingdevices. Thus, it is a specific object of this invention to provide anovel and improved actuating mechanism or arrangement for operating themovable platen or die carrier of a large electric resistance flashbuttwelding machine whereby a gauging device having ted States Patentparallel gauging faces may be advantageously employed. Morespecifically, it is anobject of the invention to Patented May 28, 1957provide a novel actuating mechanism for large electric resistanceflash-butt welders whereby the welding platens may be readily separatedfollowing the gauging operation so that the gauging bar may be removedwithout damaging the ends of the material to be welded.

Yet another and still more specific object of the invention is theprovision of a novel actuating device for the movable platen of a largeelectric resistance welding device comprising a large diameterrelatively long stroke main hydraulic actuating device and a seriesconnected small diameter relatively short stroke auxiliary hydraulicactuating device, the arrangement being such that following a gaugingoperation the movable platen is retracted by the small diameter actuatoror actuators, whereupon the flashing and upset operations are'carriedout by means of the main actuator or actuators. The arrangement is suchthat the use of a spacer or gauge bar with parallel gauge faces isrendered consistent with the general objectives of speed in operationand accurate control of the movable die members during all phases of thewelding procedure.

The above and other objects and advantages of ourv invention will becomeapparent upon full consideration of the following detailed specificationand accompanying drawing wherein is illustrated a certain preferredembodiment of our invention.

In the drawing:

Figure 1 is a fragmentary side elevation of a flash-butt strip Welderconstructed in accordance with the teachings of our invention;

Figures 25 are fragmentary section views of the apparatus of Figure 1illustrating the same in various oper ating positions; and

Figures 6-8 are fragmentary section views of the apparatus of Figure 1showing particularly our novel arrangement for controlling the movementof the welder dies.

In Figure l the reference numeral 10 designates a fixed machine baseupon which is mounted, in accordance with usual welding practice, afixed platen 11 and movable platen 12. Fixed platen 11 is secured to thebase 10 in normally fixed relation but may be provided with conventionaladjustments, not shown, for obtaining proper strip alignment. Theillustrated apparatus contemplates the accommodation of strip of widthsin excess of fifty to sixty inches, and accordingly platen 11 comprisesa pair of spaced upstanding frame members 13 whereby the strip, notshown, my pass longitudinally of the welding apparatus,-or for examplein a direction from platen 12 to platen 11, between the spaced framemembers 13. A pair of die members 14 and 15 are carried by the fixedplaten 11 for clamping the end portion of a strip to be welded, and itwill be understood that the apparatus of Figure 1 includes such controland structure as is necessary to apply adequate clamping pressurebetween the die members 14 and 15. A preferred structure for thispurpose is disclosed in our copending related application Ser. No.282,766, now U. S. Patent No. 2,710,903, filed April 17, 1952, entitledWork Holding Apparatus for Flash-Butt Welding Machines.

Movable platen 12 is constructed similarly to the fixed platen 11,including spaced upstanding frame members 16 and upper and lower diemembers 17 and 18, and is conventionally mounted on base 10 for slidablemovement toward and away from fixed platen 11.

Normal operation of flash-butt welding apparatus of the type hereinillustrated comprises a first step of positioning platen 12 apredetermined distance from the fixed platen 11. The trailing andleading end portions of two successive coils or sheets are then properlyspaced relative to the platens 11 and 12 whereupon die members 14 and.15, and 17 and 18 are caused to closeto firmly clamp 3 theendportionsin'the'de'sired relation. The actual welding "operation may then becarried "out'by "causing electric current to pass through the contiguousend surfaces of each of the strips or coils while eifecting suitable.a'dvancingor closing movements of the movable platenil2i 5 in thedirection of the fixed platen 11.

Our apparatus incorporates, for the purposeof-spacing, adjacent stripends, a spacer bar member. 19- 'having a plurality of parallel. gaugingfaces thereon,..each .of a different gaugingthickness. In the preferredmode of operation spacer bar 19.'is disposed. vertically and is insertedbetween the. fixed and'movable platens 11.and 12. as shown in Figure 4,for example,..wher.eby upon sub-. sequent. movement .of strips..20' and21 towardeach other. the end'surface of. each ofthe. stripswillaabutopposite gauge. faces of the spacer bar 19 and will accordingly bemaintained. in. a predetermined. .separationj lt-twilltbei understood.that .prior. ,to the: insertionof space: bar 19 platensll and 12areproperly prepositioneddna Work. loading? position, and thuswhen thestripsa20 andaZL 20 abut the spacer bar 19 the cooperatingdieamembers:of.- each. platen may beclosed under pressure rtozproperlyclampihe strip v ends in readiness fora welding; operation;

Spacer bar 19 is rigidly secured at its pper-radio.

a .vertically. disposed carrier. member 22 which is; adapted in a;manner to'be subsequently described- .to supportand guide the bar 19 in.m ovementzto and'fromgauginggand. retracted positions. Pivotally;secured .to;.the.'upp er; end

of carrier member 22 is a short link-:23'whichds in turn. pivotallysecured to a lever arm 24. Lever. arrrrg24, as

shownzina Figure l,ispivotallymountedzon the fi'xedplaten-.11-.by'-means'.of a shaft 26, and .itwill'rbe readily observedthat pivotal movement of the 1637617131111 24.will. cause carrier'memberi22 and spacer bar 19 to bemoved verticallyiupwardror downwardand also horizontally to at certain extent due to the presence of ahorizontal com-- ponent. in the.xar'cuate:-movement of the .lever 24.

While;.the present'rdescription refers to a single. leverarm-24- andc'arrien22,.it will be understood thataspa'ced pair of such arms andcarriers is preferably provided; i.:e.',pone'-atr"each' end. of thespacer bar: 19, andthat-a larger :number: may. be utilized if desiredwhere unusuallywide'strip or sheet metal is to be accommodated. Wheremore;than- .one. lever arm and carrier are utilized suitable".interconnectingmeansmay be provided to synchronize the movementtth'ereofas will be readily appreciated.

Lever arma24 is motivatedby means of a conventional fluidoperatedactuating deViceZS, the cylinder 'part'of whichismou'nted on theframeimember 13'while-the pis=' ton rodis :connected to the lever arm-24outwardly 0f 60 theapoint' of-"pivotal mounting thereof 33 suitable ap'pli'cation of'.fiuid' 'pressuretothe actuator 25 lever'arm 24-may be;causedto=pivot in aclcckwise or counter clockwise di'rection as may bedesired;

Securedto-each end of the spacer bar member'19 isa" guide-bar 27 whichis'preferably' slightly wider than the. spacer--bar-19 and extends'bel'owthe lower end extremity thereof. For'cooperation with the guidebars 27 we have providedat'eachiend corner of each of the die: members14 18: a hardened 'guidei block 28. Thus, by appropriate prepositioningof the movable platen 12 with respectto the fixed platen 11 preparatoryto inser-tingtherebetvieen. spacer bar 19, the latter may be providedwith accurate and rigid guidance in vertically upward or downward 65movement. .The position of the movable platen 12'wherein guide blocks 28.are "properly. separated for the-insertion and accurate guidance ofguide bars 27 is commonly referred. to as the workloading position,and-(where desired; suitable. automatic control means'may be rincor-z 70porated .into the welding apparatus to 50 position :"the=- movableplaten lzj-aftereach welding operation.

.It will-.be-noted in respectto'the: vertically'gnided: movementof: thespacergbar' 19.. that while movement of"! flieeleyersarm; -2I4-'is:.-purely arcuate: the member: 23-1.;175

d; permits movement of the carrier 22 in a horizontaldirectionwithresp'ect-to the-point of suspension thereof from the leverarm 24. This will be apparent from comparison of Figures 3 and 4.

The rigid and accurate guidance of spacer bar 19 afforded by the guidebars 27 and blocks 28 is advantageous in two important respects. First,feeding of the strip. ends into gauging contact with the spacer bar 19is commonly accomplished by means of pinch rolls 29 and 30 which arenecessarily inertia laden. By rigidly restraining the bar 19 We preventit beingmisaligned by impact thereagainst of the inwardly moving strip.Secondly, we have'g-found it desirable to incorporate in thegaugingapparatus means for trimming weld flash and other foreign matterfroni'the adjacent faces of the die members and electrode bars 31 andpressure bars 31' mounted thereon. Thus, by accurately guiding themovement of the spacer bar 19 we have been able to mount thereon a pairof horizontally. disposed cutter' bars 32: which'aresoarranged as to.pass over'the faces of the die 1nembers'14 18 and electrode andpressure bars 31 and 31' during downward movement of the spacer bar 19-.

According to the teachings of the invention spacer bar 19: and thesupporting and operating elements therefor are so proportioned thatlever. arm 24 isapproximately horizontally disposedwhen the spacer. bar19-is in a gauging position, but is directed substantially upward fromthehorizontal when spacer bar-19 is withdrawn upwardly into a retractedposition. The arrangement is suchthat the. point of suspension ofcarrier 22 is moved substantially to the left as shown in Figure 2, and.ac-

cordingly spacer bar 19 hangstherefrom ina position. substantially tothe left of the point of'meeting of'the strip; sections to .be welded.The spacer bar .is.:thereby protected from. direct impingement of :flashduring. the welding-.operati0n.. Maintenancectime on the spacerapparatus is: thusreduced to.a practical minimum.

Inxmovingthe spacerbar 19 froma retracted and .inoperative position asshown in Figure 2. to operating positionebetweenplatens 11 and;12.it isimportant'that the b31319 be properly inserted between theguide block 23so that the guide bar.27 will not'bind during the initial stages oftheinsertion; To this end we have provided a keyway 33 in carrier 22which is adapted for cooperating engagement withla'key 34 whichisrigidly mounted on the fixed platen '11... For a purpose'which willsubsequently bejdisclosed,..keyway 33 is somewhat wider than-is key 34so that carrier 22 may be loosely guided thereby initsfverticalmovement.

Asxwillilbesapparent from the drawing, the'key 34 isso'orientedonthefixed platen 11 that engagement thereof with thexkeyway33' in carrier 22 begins during-the initial insertion of the guide bar27 between blocks 28. Thus.

portion to -fa'cilitate initial entry into the upper guideb1ocks 28:

After'spacerbar-19 is initially inserted between platens 11 and 12 itis'causedto move; by continued application of fluid pressure to theupper end of actuator 25, to a fully downward "position .as shownin-Figure- 3. When the apparatus-'has reached this position cutterbars32 have moved completelyacross the faces of the lower electrode bars3l'and' the pressure bars 31- and the same are there by free ofinterfering flash particles and are" in readiness for a new :weldingoperation. Fluid is thenapplied to the lower end of =actuator 25 tocause leverrarm 24 to move-upwardly a predetermined distance topositionone of'tlre' plurality of gauge'fac'es of'the'spacer bar'19'oppo- Motivepower is thenzapp'lied to pinch 'rolls '29 and 30 to cause" stripysectionsrto move'inwardly from both directions:

site electrodebars'31 and; pressure bars 31 towardathe: igauge' faces tot" bar 19; and the pinch .rolls 5 are of course stopped when theinwardly moving strip sections abut the spacer bar. Upon subsequentremoval of the bar 19 to its retracted and protected upper position thewelding operation may proceed by appropriate inward movement of platen12 and application of welding energy to the electrode bars 31. a 1,

Successful use of a spacer bar having parallel rather than tapered gaugefaces requires that the platens 11 and 12 be slightly separated beforethe spacer bar iswithdrawn to relieve the pressure exerted thereon bythe clamped strip sections. This is particularly important where thinstock is to be welded inasmuch as the frictional drag of the endsurfaces of the strip upon the gauge" faces tends to cause upwardturning of the strip endsthe occurrence of which would be prohibitive tocarrying out a satisfactory welding operation. Such separation is alsodesirable to prevent unnecessary wear upon the gauge face as will bereadily understood.

To permit platens 11 and 12 to be slightly separated for withdrawal ofthe spacer bar 19 while maintaining operation of the apparatusconsistent with the general objectives of speed and accuracy of platenmovement we have provided a novel actuating arrangement for the movableplaten 12, which arrangement is illustrated in Figure 1, andschematically in Figures 6-8. Referring particularly to the schematicrepresentations in Figures 6-8 it will be observed that the pistonmember35 of a small diameter short stroke hydraulic actuator 36 is rigidlyconnected to the movable platen 12 by means of a bracket 37. Preferablythe piston 35 is substantially aligned horizontally with the pass lineof; the strip sections to be welded whereby forces applied to the platen12 will be properly balanced. And it will be understood that movingforce is preferably applied to each side of the platen 12 by duplicateactuating devices positioned in straddling relation to the strip. Thisis in accordance with usual strip welded construction.

Rigidly connected to the cylinder of actuator 36 is the piston rod 38 ofa large diameter relatively long stroke hydraulic actuator 39, knownconventionally as an upset cylinder. In the illustrated apparatus apiston rod 38 extends outwardly of both ends of the upset cylinder 39and is provided with means, such as adjustable bucking nuts 40 and 41,for limiting movement of the rod' 38 in either longitudinal direction.Nut 40 may be used, for example, to normally limit retracting movementof movable platen 12 to movement into the work loading position, whilenut 41 may be used to control the final die opening or the ultimatespacing of the die members at the end of the welding operation. Nut 41particularly should be readily adjustable to provide upset adjustmentfor strip sections of various thicknesses. A preferred arrangement forproviding upset adjustment is fully disclosed in our co-pending relatedapplication Ser. No. 286,042, filed May 5, 1952, entitled Die SpacingMeans for Welding Apparatus, now U. S. Patent No. 2,63 6,966, issuedApril 28, 1953.

As will be observed in Figures 6-8, the right hand end of actuator 36 isprovided internally with a circular land or abutment against whichpiston 35 is adapted to rigidly bottom upon application of fluidpressure to the rod end of actuator 35 through conduit 42. According tothe principles of the invention, fluid pressure is applied to the smallactuator 35 substantially at all times through conduit 42, andaccordingly, when pressure is applied to the head end of actuator 39through conduit 43 force is transmitted to the movable platen 12 by adirect and rigid metal-to-metal contact through the small actuator 36.Thus the necessarily large upset pressures may be applied independentlyof the actuator 36 in the manner illustrated in Figure 8.

At the end of a welding operation fluid pressure may be appliedsimultaneously to actuators 36 and 39 through conduits 44 and 45respectively, causing piston rod 38 and actuator 36 to move to the rightand piston 35 to move to the left with respect to actuator 36. Upon thenut 40 reaching its limit stop, as shown in Figure 6, further movementof piston rod 38 to the right is prevented and movement of piston 35 tothe left with respect to the actuator 36 is positively limited as piston35 bottoms against the left hand end of the actuator. It should thus beapparent-that by proper adjustment of nut 40 we may provide that withactuators 36 and 39 conditioned as shown in Figure 6 the movable platen12 will be accurately' positioned in the work loading position. Cleaningof the dies, and feeding and spacing of the workpieces may then beeffected in the manner previously described.

With the workpieces properly spaced and clamped, fluid pressure may beapplied to conduit 42 leading into the left hand end of actuator 36.Piston 35, and movable platen 12, are thereby caused to move to theright until the piston 35 bottoms at the right hand end of actuator 36,whereupon the connection between piston rod 38 and the movable platen12' will again be direct and rigid. In this operation all pressure isrelieved from the spacer bar 19 and from the guide bars 27 therefor, andthe same may be moved into a retracted position by application of fluidpressure to the lower end of actuator 25. It is contemplated that thepiston 35 will have a relatively short operating stroke, as for exampleone or two inches, and that the fluid displacement required in movingthe piston 35 through its full operating stroke will be extremelylow-'sufiicient only to overcome the sliding friction of theapparatuswhereby the short retracting movement of the platen 12 may becarried out in a minimum of time.

As a further means of preventing unnecessary wear upon the gauge facesof spacer bar 19 and/ or multilation of the end portions of thinworkpieces, we have provided a novel arrangement whereby the spacer bar19, upon platen 12 being moved into a retracted position as in Figure 8,is caused to swing outwardly of the platen 11 to a positionsubstantially centrally intermediate the fixed and movable platens 11and 12.

As illustrated in Figure 4, lever arm 24 is so proportioned that itspoint of pivotal connection with link 23 (point A) lies to the right tothe point of pivotal connection of the link 23 with carrier 22 (point B)at all times when spacer bar 19 is positioned so as to present a gaugingface at the pass line of the strip sections 20 and 21. Although Figure 4illustrates the use of the widest gauge faces only, the above fact maybe readily ascertained by noting that point A will continue to moveoutwardly a slight amount as the spacer bar 19 is raised to present newgauging faces to the pass line. Point B is of course confined tomovement along the vertical longitudinal axis of the spacer bar 19 byvirtue of the heretofore described guiding means provided for the spacerbar 19.

Thus, it will be apparent that upon releasing movement of the movableplaten 12 by application of fluid pressure through conduit 42, spacerbar 19 will, by the action of gravity, tend to move outwardly of themovable platen 11 and thus away from the die members 14 and 15 thereof.By providing a certain measure of looseness between key 34 and keyway 33provided in the carrier 22 we have provided that the spacer bar 19 mayswing by gravity to a point substantially centrally intermediate theseparated platens 11 and 12, as shown in Figure 5, from which positionthe bar 19 may be withdrawn into a retracted position without contactingthe end surfaces of either of the clamped strip sections 20 or 21.

In the preferred construction of the apparatus keyway 33 and key 34 areso dimensioned that contact is made between one surface of the keyway 33and key 34 when the bar 19 is vertically guided by means of guide bar 27and blocks 28, and contact is made between opposite surfaces of members33 and 34 to limit outward swinging movement of the bar 19 to a positionspaced from both platens 11 and 12.

- The advantages of our invention should now be apparent. We haveprovided a wholly practical arrangement for utilizing a strip spacingmember having a plurality of stepped pairs of parallel gauge faceswhereby a flat abutment is afforded for contact by inwardly moving stripsections. Heretofore slightly tapered gauge surfaces have been commonlyprovided whereby upon a short withdrawal movement of the spacing orgauging member the gauging surfaces were automatically drawn away fromthe end surfaces of the strip sections.

We have found such tapered surfaces to be undesirable, however,particularly for thin material since a skewed contact with the stripends is inherent in such apparatus, and a slight turning-up of the endportions of the material inevitably results. Our invention, on the otherhand, teaches the use of parallel gauging surfaces with a novelarrangement for rapidly withdrawing the movable platen 12 whereby thespacer bar 19 moves away from the end surfaces of the strip and may bereadily withdrawn into a retracted position.

By providing large and small platen actuating members,

arranged in series relation and independently operable,

the movable platen 12 may be quickly retracted for removal of thespacing bar 19, and it is important to note that the upset cylinder 39remains wholly unafi'ected during such retraction. While the upsetcylinder must necessarily be of large diameter to properly carry out thewelding operation, the series connected actuator 36 may be of smalldiameter and short stroke whereby the same may be operated in apractical minimum of time from a hydraulic power source of normalcapacity. Our arrangement further provides that during the flashing andupset portions of a complete welding cycle a direct and rigid connectionexists between the upset cylinder 39 and the.

movable platen 12 through the interposed actuator 36.

Our novel actuating device of course has possible application inapparatus other than welding apparatus, as specifically described.Moreover certain departures from the exact structure illustrated may beeflected within the .clear teachings of the invention. Reference shouldtherefore be had to the following appended claims in determining thefull scope of the invention.

We claim:

1. In combination with a flash-butt welding machine of the type having agenerally vertically movable gauge bar having parallel gauging faces, afixed platen and a movable platen adapted to be moved into a firstposition with respect to said fixed platen for the loading of workpiecesinto said platens and gauging the workpieces, to be retracted from saidfixed platen after said loading to platen during flashing and upsettingportions of a welding operation, a high power fluid actuator comprisinga fixed cylinder member and a movablepiston member, a low power fluidactuator comprising a cylinder part connected to said movable pistonmember and a piston part connected to said movable platen, said lowpower actuator having a short operating stroke and having abutmentsurfaces on said cylinder and piston parts whereby upon full retractingmovement of said piston part said piston and cylinder parts are movedinto abutting engagement, said movable piston member being therebyplaced in direct mechanical connection with said movable platen for thecarrying out of the flashing and upset portions of a welding operation.

2. In combination with a flash-butt welding machine of the type havingvertically retractable gauging means with parallel gauging surfaces, afixed platen and a movable platen adapted to be moved into a firstposition with respect to said fixed platen for the loading of workpiecesinto said platens and gauging'the workpieces, to be retracted from saidfixed platen after said loading to allow the retraction of said gaugingmeans, and to be thereafter forcibly and controllably moved toward saidfixed platen during flashing and upsetting portions of a weldingoperation, means to move said movable platen toward said fixed platenduring flashing and upset portions of a welding operation comprising ahigh power fluid actuator, and

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